Solar cells generate electricity using the photovoltaic effect of a pn junction which converts photons of sunlight into electricity. In the solar cell, front and rear electrodes are formed on upper and lower surfaces of a semiconductor wafer or substrate with the pn junctions, respectively. Then, the photovoltaic effect at the pn junction is induced by sunlight entering the semiconductor wafer and electrons generated by the photovoltaic effect at the pn junction provide electric current to the outside through the electrodes. The electrodes of the solar cell are formed on the wafer by applying, patterning, and baking an electrode composition.
Continuous reduction in emitter thickness to improve solar cell efficiency can cause shunting which can deteriorate solar cell performance. In addition, solar cells have been gradually increased in area to achieve higher efficiency. In this case, however, there can be a problem of efficiency deterioration due to increase in solar cell contact resistance.
Therefore, there is a need for a composition for solar cell electrodes that can enhance contact efficiency between electrodes and a silicon wafer to minimize contact resistance (Rc) and serial resistance (Rs), thereby providing excellent conversion efficiency.